Noroviruses are commonly associated with outbreaks of acute non-bacterial gastroenteritis in food service establishments, and hands are a principal vehicle of this transmission. Alcohol-based hand sanitizers and antibacterial foam handwashes are recently popular hand hygiene products, but little is known about their effectiveness against noroviruses on contaminated hands.
Outbreaks of human norovirus (NoV) often originate in food service establishments and the hands of food handlers are thought to be a principal vehicle for NoV transmission. Hand washing is therefore considered to be an important method to control NoV transmission. Previous studies indicated that alcohol-based hand sanitizers had a significant effect against feline calicivirus (FCV, a surrogate for human NoV) on human hands. Recently, mouse norovirus (MNV) has been considered as a more appropriate surrogate for human NoV, but questions continue as to the relevance of these viruses because both FCV and MNV belong to different calicivirus genera than the human viruses.
Skin disinfectants containing one or more lower alcohols are widely known. Disinfectants containing at least about 50 weight percent alcohol exhibit antibacterial efficacy, however the antiviral efficacy of these alcohol disinfectants depends upon the type of virus.
The antiviral efficacy of acid-containing disinfectants, and of disinfectants having an acidic pH, depends upon the type of virus. A few non-enveloped viruses, namely rhinovirus, feline calicivirus, and canine calicivirus, are believed to be at least somewhat affected by acid. See Virus Taxonomy: VIIIth Report of the International Committee On Taxonomy of Viruses, Elsevier Science & Technology Books, ISBN 0122499514, 2005, which is hereby incorporated by reference in its entirety. At least one reference suggests that a pH of less than 5 will provide efficacy against rhinovirus, and other acid labile viruses.
However, human norovirus is known to be stable at an acid pH. It is generally thought that norovirus infects humans through an oral route, and encounters and survives a highly acidic environment in the stomach. It can be likewise expected that other viruses that infect via a similar route will also be acid resistant.
Thus, while acid-containing disinfectants have been reported to have some antiviral efficacy against, for example, rhinovirus and feline calicivirus, they have insufficient efficacy against human noroviruses and other non-enveloped viruses that are acid stable.
A need continues to exist for a method for rapidly inactivating human noroviruses and other acid stable viruses. Furthermore, a need exists for alcoholic compositions that have bactericidal and virucidal efficacy and may be used topically against a broad spectrum of enveloped and non-enveloped viruses. In particular, there is a need for an antiviral composition that has efficacy against human norovirus. In addition, there is a need for an antiviral composition that does not require toxic, regulated, or sensitizing components.